One of the biggest complaints with Closed Captioning is that (CC) because it is overlaid on the video it interferes with the display of the video. It can obscure faces, gestures, and action shown in the video as well as scrolling banners that may be delivered as part of the video.
One of the ways to mitigate the problem, if allowed by the display device, is to minimize the size of the CC text so that it does not obscure as much video. This may make it difficult to read depending on how close the viewer is to the TV. And even then, the CC can be misplaced and it will obscure some critical aspect of the video. Furthermore, particularly for live events in which the broadcaster's closed captioning is typically typed in by a stenographer as people speak and thus noticeably lags the speech itself and accompanying video, the loss of synchronization is between the CC and speech is distracting and can be disorienting to hearing-impaired people who may be attempting to both lip read the speakers and read the CC.